var fs = require("fs");
var RGBColor = require("rgbcolor");
var xmldom = require('xmldom');

/*
 * canvg.js - Javascript SVG parser and renderer on Canvas
 * MIT Licensed 
 * Gabe Lerner (gabelerner@gmail.com)
 * http://code.google.com/p/canvg/
 *
 * Requires: rgbcolor.js - http://www.phpied.com/rgb-color-parser-in-javascript/
 */
(function () {
	// canvg(target, s)
	// target: canvas 元素或者 canvas 元素的 id
	// s: svg 字符串
	// opts：可选的选项
	//		 ignoreDimensions: true => 不尝试调整画布大小
	//		 ignoreClear: true => 不清除画布内容
	//		 offsetX: int => 在 x 偏移处绘制
	//		 offsetY: int => 在 y 偏移处绘制
	//		 scaleWidth: int => 水平缩放到指定宽度
	//		 scaleHeight: int => 垂直缩放到指定高度
	//		 renderCallback: function => 在第一次渲染完成后调用的函数
	//		 forceRedraw: function => 在每一帧调用的函数，如果返回 true，将重新绘制

	this.canvg = function (target, s, opts) {
		if (target == null || s == null) {
			return;
		}
		opts = opts || {};
		// store class on canvas
		target.svg = svg = build();
		svg.opts = opts;
		var ctx = target.getContext('2d');
		svg.loadXmlDoc(ctx, svg.parseXml(s));

	}

	function build() {
		var svg = {};

		svg.FRAMERATE = 30;
		svg.MAX_VIRTUAL_PIXELS = 30000;

		// globals
		svg.init = function (ctx) {
			svg.Definitions = {};
			svg.Styles = {};
			svg.Animations = [];
			svg.Images = [];
			svg.ctx = ctx;
			svg.ViewPort = new (function () {
				this.viewPorts = [];
				this.Clear = function () { this.viewPorts = []; }
				this.SetCurrent = function (width, height) { this.viewPorts.push({ width: width, height: height }); }
				this.RemoveCurrent = function () { this.viewPorts.pop(); }
				this.Current = function () { return this.viewPorts[this.viewPorts.length - 1]; }
				this.width = function () { return this.Current().width; }
				this.height = function () { return this.Current().height; }
				this.ComputeSize = function (d) {
					if (d != null && typeof (d) == 'number') return d;
					if (d == 'x') return this.width();
					if (d == 'y') return this.height();
					return Math.sqrt(Math.pow(this.width(), 2) + Math.pow(this.height(), 2)) / Math.sqrt(2);
				}
			});
		}
		svg.init();

		// images loaded
		svg.ImagesLoaded = function () {
			for (var i = 0; i < svg.Images.length; i++) {
				if (!svg.Images[i].loaded) return false;
			}
			return true;
		}

		// trim 去除字符串两端的空格
		svg.trim = function (s) { return s.replace(/^\s+|\s+$/g, ''); }

		// compress spaces 压缩字符串中的空格，包括空格、回车、制表符和换行符
		svg.compressSpaces = function (s) { return s.replace(/[\s\r\t\n]+/gm, ' '); }


		// ajax
		// svg.ajax = function (url, ajax_callback) {
		// 	http.get(url, function (res) {
		// 		var data = '';
		// 		res.on('data', function (chunk) {
		// 			data += chunk;
		// 		});
		// 		res.on('end', function () {
		// 			ajax_callback(data);
		// 		});
		// 	});
		// }

		// remote
		svg.remote = function (url, remote_callback) {
			if (url[0] === '.')
				fs.readFile(url, function (error, data) {
					if (error) throw error;

					remote_callback(data);
				})
			// else
			// http.get(url, function (res) {
			// 	var data = new Buffer(parseInt(res.headers['content-length'], 10));
			// 	var pos = 0;
			// 	res.on('data', function (chunk) {
			// 		chunk.copy(data, pos);
			// 		pos += chunk.length;
			// 	});
			// 	res.on('end', function () {
			// 		remote_callback(data);
			// 	});
			// });
		}

		// parse xml
		svg.parseXml = function (xml) {
			var parser = new xmldom.DOMParser();
			return parser.parseFromString(xml, 'text/xml');
		}

		svg.Property = function (name, value) {
			this.name = name;
			this.value = value;
		}
		svg.Property.prototype.getValue = function () {
			return this.value;
		}

		svg.Property.prototype.hasValue = function () {
			return (this.value != null && this.value !== '');
		}

		// return the numerical value of the property
		svg.Property.prototype.numValue = function () {
			if (!this.hasValue()) return 0;

			var n = parseFloat(this.value);
			if ((this.value + '').match(/%$/)) {
				n = n / 100.0;
			}
			return n;
		}

		svg.Property.prototype.valueOrDefault = function (def) {
			if (this.hasValue()) return this.value;
			return def;
		}

		svg.Property.prototype.numValueOrDefault = function (def) {
			if (this.hasValue()) return this.numValue();
			return def;
		}

		// 颜色扩展
		// 用不透明度增强当前颜色值
		svg.Property.prototype.addOpacity = function (opacity) {
			var newValue = this.value;
			if (opacity != null && opacity != '' && typeof (this.value) == 'string') { // 只能为颜色添加不透明度，不能用于模式
				var color = new RGBColor(this.value);
				if (color.ok) {
					newValue = 'rgba(' + color.r + ', ' + color.g + ', ' + color.b + ', ' + opacity + ')';
				}
			}
			return new svg.Property(this.name, newValue);
		}

		// 定义扩展
		// 从定义表中获取定义
		svg.Property.prototype.getDefinition = function () {
			var name = this.value.replace(/^(url\()?#([^\)]+)\)?$/, '$2');
			return svg.Definitions[name];
		}

		svg.Property.prototype.isUrlDefinition = function () {
			return this.value.indexOf('url(') == 0
		}

		svg.Property.prototype.getFillStyleDefinition = function (e) {
			var def = this.getDefinition();

			// gradient
			if (def != null && def.createGradient) {
				return def.createGradient(svg.ctx, e);
			}

			// pattern
			if (def != null && def.createPattern) {
				return def.createPattern(svg.ctx, e);
			}

			return null;
		}

		// length extensions 获取 DPI（每英寸像素数）
		svg.Property.prototype.getDPI = function (viewPort) {
			return 96.0; // TODO: compute?
		}

		// 获取 EM 单位的大小
		svg.Property.prototype.getEM = function (viewPort) {
			var em = 12;

			var fontSize = new svg.Property('fontSize', svg.Font.Parse(svg.ctx.font).fontSize);
			if (fontSize.hasValue()) em = fontSize.toPixels(viewPort);

			return em;
		}

		// 获取属性的单位（如 px、em、pt 等）
		svg.Property.prototype.getUnits = function () {
			var s = this.value + '';
			return s.replace(/[0-9\.\-]/g, '');
		}

		// get the length as pixels
		svg.Property.prototype.toPixels = function (viewPort) {
			if (!this.hasValue()) return 0;
			var s = this.value + '';
			if (s.match(/em$/)) return this.numValue() * this.getEM(viewPort);
			if (s.match(/ex$/)) return this.numValue() * this.getEM(viewPort) / 2.0;
			if (s.match(/px$/)) return this.numValue();
			if (s.match(/pt$/)) return this.numValue() * this.getDPI(viewPort) * (1.0 / 72.0);
			if (s.match(/pc$/)) return this.numValue() * 15;
			if (s.match(/cm$/)) return this.numValue() * this.getDPI(viewPort) / 2.54;
			if (s.match(/mm$/)) return this.numValue() * this.getDPI(viewPort) / 25.4;
			if (s.match(/in$/)) return this.numValue() * this.getDPI(viewPort);
			if (s.match(/%$/)) return this.numValue() * svg.ViewPort.ComputeSize(viewPort);
			return this.numValue();
		}

		// 时间拓展
		// 以 ms 为单位获取时间
		svg.Property.prototype.toMilliseconds = function () {
			if (!this.hasValue()) return 0;
			var s = this.value + '';
			if (s.match(/s$/)) return this.numValue() * 1000;
			if (s.match(/ms$/)) return this.numValue();
			return this.numValue();
		}

		// 角度拓展
		// 以弧度为单位获取角度
		svg.Property.prototype.toRadians = function () {
			if (!this.hasValue()) return 0;
			var s = this.value + '';
			if (s.match(/deg$/)) return this.numValue() * (Math.PI / 180.0);
			if (s.match(/grad$/)) return this.numValue() * (Math.PI / 200.0);
			if (s.match(/rad$/)) return this.numValue();
			return this.numValue() * (Math.PI / 180.0);
		}

		// 字体
		svg.Font = new (function () {
			this.Styles = 'normal|italic|oblique|inherit'; // 字体样式的可选项
			this.Variants = 'normal|small-caps|inherit'; // 字体变体
			this.Weights = 'normal|bold|bolder|lighter|100|200|300|400|500|600|700|800|900|inherit'; // 权重的合法取值

			// 创建字体对象，返回字体对象的属性
			this.CreateFont = function (fontStyle, fontVariant, fontWeight, fontSize, fontFamily, inherit) {
				var f = inherit != null ? this.Parse(inherit) : this.CreateFont('', '', '', '', '', svg.ctx.font);
				return {
					fontFamily: fontFamily || f.fontFamily,
					fontSize: fontSize || f.fontSize,
					fontStyle: fontStyle || f.fontStyle,
					fontWeight: fontWeight || f.fontWeight,
					fontVariant: fontVariant || f.fontVariant,
					toString: function () { return [this.fontStyle, this.fontVariant, this.fontWeight, this.fontSize, this.fontFamily].join(' ') }
				}
			}

			var that = this;
			// 解析字体字符串，
			this.Parse = function (s) {
				var f = {};
				var d = svg.trim(svg.compressSpaces(s || '')).split(' ');
				// 跟踪已经解析的字体属性，确保每种属性只设置一次
				var set = { fontSize: false, fontStyle: false, fontWeight: false, fontVariant: false }
				var ff = '';
				for (var i = 0; i < d.length; i++) {
					if (!set.fontStyle && that.Styles.indexOf(d[i]) != -1) { if (d[i] != 'inherit') f.fontStyle = d[i]; set.fontStyle = true; }
					else if (!set.fontVariant && that.Variants.indexOf(d[i]) != -1) { if (d[i] != 'inherit') f.fontVariant = d[i]; set.fontStyle = set.fontVariant = true; }
					else if (!set.fontWeight && that.Weights.indexOf(d[i]) != -1) { if (d[i] != 'inherit') f.fontWeight = d[i]; set.fontStyle = set.fontVariant = set.fontWeight = true; }
					else if (!set.fontSize) { if (d[i] != 'inherit') f.fontSize = d[i].split('/')[0]; set.fontStyle = set.fontVariant = set.fontWeight = set.fontSize = true; }
					else { if (d[i] != 'inherit') ff += d[i]; }
				} if (ff != '') f.fontFamily = ff;
				return f;
			}
		});

		// 点和路径
		svg.ToNumberArray = function (s) {
			var a = svg.trim(svg.compressSpaces((s || '').replace(/,/g, ' '))).split(' ');
			for (var i = 0; i < a.length; i++) {
				a[i] = parseFloat(a[i]);
			}
			return a;
		}
		svg.Point = function (x, y) {
			this.x = x;
			this.y = y;
		}
		svg.Point.prototype.angleTo = function (p) {
			return Math.atan2(p.y - this.y, p.x - this.x);
		}

		svg.Point.prototype.applyTransform = function (v) {
			var xp = this.x * v[0] + this.y * v[2] + v[4];
			var yp = this.x * v[1] + this.y * v[3] + v[5];
			this.x = xp;
			this.y = yp;
		}

		svg.CreatePoint = function (s) {
			var a = svg.ToNumberArray(s);
			return new svg.Point(a[0], a[1]);
		}
		svg.CreatePath = function (s) {
			var a = svg.ToNumberArray(s);
			var path = [];
			for (var i = 0; i < a.length; i += 2) {
				path.push(new svg.Point(a[i], a[i + 1]));
			}
			return path;
		}

		// bounding box
		svg.BoundingBox = function (x1, y1, x2, y2) { // pass in initial points if you want
			this.x1 = Number.NaN;
			this.y1 = Number.NaN;
			this.x2 = Number.NaN;
			this.y2 = Number.NaN;

			this.x = function () { return this.x1; }
			this.y = function () { return this.y1; }
			this.width = function () { return this.x2 - this.x1; }
			this.height = function () { return this.y2 - this.y1; }

			this.addPoint = function (x, y) {
				if (x != null) {
					if (isNaN(this.x1) || isNaN(this.x2)) {
						this.x1 = x;
						this.x2 = x;
					}
					if (x < this.x1) this.x1 = x;
					if (x > this.x2) this.x2 = x;
				}

				if (y != null) {
					if (isNaN(this.y1) || isNaN(this.y2)) {
						this.y1 = y;
						this.y2 = y;
					}
					if (y < this.y1) this.y1 = y;
					if (y > this.y2) this.y2 = y;
				}
			}
			this.addX = function (x) { this.addPoint(x, null); }
			this.addY = function (y) { this.addPoint(null, y); }

			this.addBoundingBox = function (bb) {
				this.addPoint(bb.x1, bb.y1);
				this.addPoint(bb.x2, bb.y2);
			}

			this.addQuadraticCurve = function (p0x, p0y, p1x, p1y, p2x, p2y) {
				var cp1x = p0x + 2 / 3 * (p1x - p0x); // CP1 = QP0 + 2/3 *(QP1-QP0)
				var cp1y = p0y + 2 / 3 * (p1y - p0y); // CP1 = QP0 + 2/3 *(QP1-QP0)
				var cp2x = cp1x + 1 / 3 * (p2x - p0x); // CP2 = CP1 + 1/3 *(QP2-QP0)
				var cp2y = cp1y + 1 / 3 * (p2y - p0y); // CP2 = CP1 + 1/3 *(QP2-QP0)
				this.addBezierCurve(p0x, p0y, cp1x, cp2x, cp1y, cp2y, p2x, p2y);
			}

			this.addBezierCurve = function (p0x, p0y, p1x, p1y, p2x, p2y, p3x, p3y) {
				// from http://blog.hackers-cafe.net/2009/06/how-to-calculate-bezier-curves-bounding.html
				var p0 = [p0x, p0y], p1 = [p1x, p1y], p2 = [p2x, p2y], p3 = [p3x, p3y];
				this.addPoint(p0[0], p0[1]);
				this.addPoint(p3[0], p3[1]);

				for (i = 0; i <= 1; i++) {
					var f = function (t) {
						return Math.pow(1 - t, 3) * p0[i]
							+ 3 * Math.pow(1 - t, 2) * t * p1[i]
							+ 3 * (1 - t) * Math.pow(t, 2) * p2[i]
							+ Math.pow(t, 3) * p3[i]; //三次贝塞尔曲线
					}

					var b = 6 * p0[i] - 12 * p1[i] + 6 * p2[i];
					var a = -3 * p0[i] + 9 * p1[i] - 9 * p2[i] + 3 * p3[i];
					var c = 3 * p1[i] - 3 * p0[i];

					if (a == 0) {
						if (b == 0) continue;
						var t = -c / b;
						if (0 < t && t < 1) {
							if (i == 0) this.addX(f(t));
							if (i == 1) this.addY(f(t));
						}
						continue;
					}

					var b2ac = Math.pow(b, 2) - 4 * c * a;
					if (b2ac < 0) continue;
					var t1 = (-b + Math.sqrt(b2ac)) / (2 * a);
					if (0 < t1 && t1 < 1) {
						if (i == 0) this.addX(f(t1));
						if (i == 1) this.addY(f(t1));
					}
					var t2 = (-b - Math.sqrt(b2ac)) / (2 * a);
					if (0 < t2 && t2 < 1) {
						if (i == 0) this.addX(f(t2));
						if (i == 1) this.addY(f(t2));
					}
				}
			}

			this.isPointInBox = function (x, y) {
				return (this.x1 <= x && x <= this.x2 && this.y1 <= y && y <= this.y2);
			}

			this.addPoint(x1, y1); // 添加起点
			this.addPoint(x2, y2); // 添加终点
		}

		// transforms
		svg.Transform = function (v) {
			var that = this;
			this.Type = {}

			// translate
			this.Type.translate = function (s) {
				this.p = svg.CreatePoint(s);
				this.apply = function (ctx) {
					ctx.translate(this.p.x || 0.0, this.p.y || 0.0);
				}
				this.applyToPoint = function (p) {
					p.applyTransform([1, 0, 0, 1, this.p.x || 0.0, this.p.y || 0.0]);
				}
			}

			// rotate
			this.Type.rotate = function (s) {
				var a = svg.ToNumberArray(s);
				this.angle = new svg.Property('angle', a[0]);
				this.cx = a[1] || 0;
				this.cy = a[2] || 0;
				this.apply = function (ctx) {
					ctx.translate(this.cx, this.cy);
					ctx.rotate(this.angle.toRadians());
					ctx.translate(-this.cx, -this.cy);
				}
				this.applyToPoint = function (p) {
					var a = this.angle.toRadians();
					p.applyTransform([1, 0, 0, 1, this.p.x || 0.0, this.p.y || 0.0]);
					p.applyTransform([Math.cos(a), Math.sin(a), -Math.sin(a), Math.cos(a), 0, 0]);
					p.applyTransform([1, 0, 0, 1, -this.p.x || 0.0, -this.p.y || 0.0]);
				}
			}

			this.Type.scale = function (s) {
				this.p = svg.CreatePoint(s);
				this.apply = function (ctx) {
					ctx.scale(this.p.x || 1.0, this.p.y || this.p.x || 1.0);
				}
				this.applyToPoint = function (p) {
					p.applyTransform([this.p.x || 0.0, 0, 0, this.p.y || 0.0, 0, 0]);
				}
			}

			this.Type.matrix = function (s) {
				this.m = svg.ToNumberArray(s);
				this.apply = function (ctx) {
					ctx.transform(this.m[0], this.m[1], this.m[2], this.m[3], this.m[4], this.m[5]);
				}
				this.applyToPoint = function (p) {
					p.applyTransform(this.m);
				}
			}

			this.Type.SkewBase = function (s) {
				this.base = that.Type.matrix;
				this.base(s);
				this.angle = new svg.Property('angle', s);
			}
			this.Type.SkewBase.prototype = new this.Type.matrix;

			this.Type.skewX = function (s) {
				this.base = that.Type.SkewBase;
				this.base(s);
				this.m = [1, 0, Math.tan(this.angle.toRadians()), 1, 0, 0];
			}
			this.Type.skewX.prototype = new this.Type.SkewBase;

			this.Type.skewY = function (s) {
				this.base = that.Type.SkewBase;
				this.base(s);
				this.m = [1, Math.tan(this.angle.toRadians()), 0, 1, 0, 0];
			}
			this.Type.skewY.prototype = new this.Type.SkewBase;

			this.transforms = [];

			this.apply = function (ctx) {
				for (var i = 0; i < this.transforms.length; i++) {
					this.transforms[i].apply(ctx);
				}
			}

			this.applyToPoint = function (p) {
				for (var i = 0; i < this.transforms.length; i++) {
					this.transforms[i].applyToPoint(p);
				}
			}

			var data = svg.trim(svg.compressSpaces(v)).split(/\s(?=[a-z])/);
			for (var i = 0; i < data.length; i++) {
				var type = data[i].split('(')[0];
				var s = data[i].split('(')[1].replace(')', '');
				var transform = new this.Type[type](s);
				this.transforms.push(transform);
			}
		}

		// aspect ratio
		svg.AspectRatio = function (ctx, aspectRatio, width, desiredWidth, height, desiredHeight, minX, minY, refX, refY) {
			// aspect ratio - http://www.w3.org/TR/SVG/coords.html#PreserveAspectRatioAttribute
			aspectRatio = svg.compressSpaces(aspectRatio);
			aspectRatio = aspectRatio.replace(/^defer\s/, ''); // ignore defer
			var align = aspectRatio.split(' ')[0] || 'xMidYMid';
			var meetOrSlice = aspectRatio.split(' ')[1] || 'meet';

			// calculate scale
			var scaleX = width / desiredWidth;
			var scaleY = height / desiredHeight;
			var scaleMin = Math.min(scaleX, scaleY);
			var scaleMax = Math.max(scaleX, scaleY);
			if (meetOrSlice == 'meet') { desiredWidth *= scaleMin; desiredHeight *= scaleMin; }
			if (meetOrSlice == 'slice') { desiredWidth *= scaleMax; desiredHeight *= scaleMax; }

			refX = new svg.Property('refX', refX);
			refY = new svg.Property('refY', refY);
			if (refX.hasValue() && refY.hasValue()) {
				ctx.translate(-scaleMin * refX.toPixels('x'), -scaleMin * refY.toPixels('y'));
			}
			else {
				// align
				if (align.match(/^xMid/) && ((meetOrSlice == 'meet' && scaleMin == scaleY) || (meetOrSlice == 'slice' && scaleMax == scaleY))) ctx.translate(width / 2.0 - desiredWidth / 2.0, 0);
				if (align.match(/YMid$/) && ((meetOrSlice == 'meet' && scaleMin == scaleX) || (meetOrSlice == 'slice' && scaleMax == scaleX))) ctx.translate(0, height / 2.0 - desiredHeight / 2.0);
				if (align.match(/^xMax/) && ((meetOrSlice == 'meet' && scaleMin == scaleY) || (meetOrSlice == 'slice' && scaleMax == scaleY))) ctx.translate(width - desiredWidth, 0);
				if (align.match(/YMax$/) && ((meetOrSlice == 'meet' && scaleMin == scaleX) || (meetOrSlice == 'slice' && scaleMax == scaleX))) ctx.translate(0, height - desiredHeight);
			}

			// scale
			if (align == 'none') ctx.scale(scaleX, scaleY);
			else if (meetOrSlice == 'meet') ctx.scale(scaleMin, scaleMin);
			else if (meetOrSlice == 'slice') ctx.scale(scaleMax, scaleMax);

			// translate
			ctx.translate(minX == null ? 0 : -minX, minY == null ? 0 : -minY);
		}

		// elements
		svg.Element = {}

		svg.EmptyProperty = new svg.Property('EMPTY', '');

		svg.Element.ElementBase = function (node) {
			this.attributes = {};
			this.styles = {};
			this.children = [];

			// get or create attribute
			this.attribute = function (name, createIfNotExists) {
				var a = this.attributes[name];
				if (a != null) return a;

				if (createIfNotExists == true) { a = new svg.Property(name, ''); this.attributes[name] = a; }
				return a || svg.EmptyProperty;
			}

			// get or create style, crawls up node tree
			this.style = function (name, createIfNotExists) {
				var s = this.styles[name];
				if (s != null) return s;

				var a = this.attribute(name);
				if (a != null && a.hasValue()) {
					this.styles[name] = a; // move up to me to cache
					return a;
				}

				var p = this.parent;
				if (p != null) {
					var ps = p.style(name);
					if (ps != null && ps.hasValue()) {
						return ps;
					}
				}

				if (createIfNotExists == true) { s = new svg.Property(name, ''); this.styles[name] = s; }
				return s || svg.EmptyProperty;
			}

			// base render
			this.render = function (ctx) {
				// don't render display=none
				if (this.style('display').value == 'none') return;

				// don't render visibility=hidden
				if (this.attribute('visibility').value == 'hidden') return;

				ctx.save();
				this.setContext(ctx);
				// mask
				if (this.attribute('mask').hasValue()) {
					var mask = this.attribute('mask').getDefinition();
					if (mask != null) mask.apply(ctx, this);
				}
				else if (this.style('filter').hasValue()) {
					var filter = this.style('filter').getDefinition();
					if (filter != null) filter.apply(ctx, this);
				}
				else this.renderChildren(ctx);
				this.clearContext(ctx);
				ctx.restore();
			}

			// base set context
			this.setContext = function (ctx) {
				// OVERRIDE ME!
			}

			// base clear context
			this.clearContext = function (ctx) {
				// OVERRIDE ME!
			}

			// base render children
			this.renderChildren = function (ctx) {
				for (var i = 0; i < this.children.length; i++) {
					this.children[i].render(ctx);
				}
			}

			this.addChild = function (childNode, create) {
				var child = childNode;
				if (create) child = svg.CreateElement(childNode);
				child.parent = this;
				this.children.push(child);
			}

			if (node != null && node.nodeType == 1) { //ELEMENT_NODE
				// add children
				for (var i = 0; i < node.childNodes.length; i++) {
					var childNode = node.childNodes[i];
					if (childNode.nodeType == 1) this.addChild(childNode, true); //ELEMENT_NODE
				}

				// add attributes
				for (var i = 0; i < node.attributes.length; i++) {
					var attribute = node.attributes[i];
					this.attributes[attribute.nodeName] = new svg.Property(attribute.nodeName, attribute.nodeValue);
				}

				// add tag styles
				var styles = svg.Styles[node.nodeName];
				if (styles != null) {
					for (var name in styles) {
						this.styles[name] = styles[name];
					}
				}

				// add class styles
				if (this.attribute('class').hasValue()) {
					var classes = svg.compressSpaces(this.attribute('class').value).split(' ');
					for (var j = 0; j < classes.length; j++) {
						styles = svg.Styles['.' + classes[j]];
						if (styles != null) {
							for (var name in styles) {
								this.styles[name] = styles[name];
							}
						}
						styles = svg.Styles[node.nodeName + '.' + classes[j]];
						if (styles != null) {
							for (var name in styles) {
								this.styles[name] = styles[name];
							}
						}
					}
				}

				// add id styles
				if (this.attribute('id').hasValue()) {
					var styles = svg.Styles['#' + this.attribute('id').value];
					if (styles != null) {
						for (var name in styles) {
							this.styles[name] = styles[name];
						}
					}
				}

				// add inline styles
				if (this.attribute('style').hasValue()) {
					var styles = this.attribute('style').value.split(';');
					for (var i = 0; i < styles.length; i++) {
						if (svg.trim(styles[i]) != '') {
							var style = styles[i].split(':');
							var name = svg.trim(style[0]);
							var value = svg.trim(style[1]);
							this.styles[name] = new svg.Property(name, value);
						}
					}
				}

				// add id
				if (this.attribute('id').hasValue()) {
					if (svg.Definitions[this.attribute('id').value] == null) {
						svg.Definitions[this.attribute('id').value] = this;
					}
				}
			}
		}

		svg.Element.RenderedElementBase = function (node) {
			this.base = svg.Element.ElementBase;
			this.base(node);

			this.setContext = function (ctx) {
				// 填充
				if (this.style('fill').isUrlDefinition()) {
					var fs = this.style('fill').getFillStyleDefinition(this);
					if (fs != null) ctx.fillStyle = fs;
				}
				else if (this.style('fill').hasValue()) {
					var fillStyle = this.style('fill');
					if (fillStyle.value == 'currentColor') fillStyle.value = this.style('color').value;
					ctx.fillStyle = (fillStyle.value == 'none' ? 'rgba(0,0,0,0)' : fillStyle.value);
				}
				if (this.style('fill-opacity').hasValue()) {
					var fillStyle = new svg.Property('fill', ctx.fillStyle);
					fillStyle = fillStyle.addOpacity(this.style('fill-opacity').value);
					ctx.fillStyle = fillStyle.value;
				}
				if (this.style('fill-rule').hasValue()) {
					ctx.fillRule = this.style('fill-rule').value;
				}

				// 描边
				if (this.style('stroke').isUrlDefinition()) {
					var fs = this.style('stroke').getFillStyleDefinition(this);
					if (fs != null) ctx.strokeStyle = fs;
				}
				else if (this.style('stroke').hasValue()) {
					var strokeStyle = this.style('stroke');
					if (strokeStyle.value == 'currentColor') strokeStyle.value = this.style('color').value;
					ctx.strokeStyle = (strokeStyle.value == 'none' ? 'rgba(0,0,0,0)' : strokeStyle.value);
				}
				if (this.style('stroke-opacity').hasValue()) {
					var strokeStyle = new svg.Property('stroke', ctx.strokeStyle);
					strokeStyle = strokeStyle.addOpacity(this.style('stroke-opacity').value);
					ctx.strokeStyle = strokeStyle.value;
				}
				if (this.style('stroke-width').hasValue()) ctx.lineWidth = this.style('stroke-width').toPixels();
				if (this.style('stroke-linecap').hasValue()) ctx.lineCap = this.style('stroke-linecap').value;
				if (this.style('stroke-linejoin').hasValue()) ctx.lineJoin = this.style('stroke-linejoin').value;
				if (this.style('stroke-miterlimit').hasValue()) ctx.miterLimit = this.style('stroke-miterlimit').value;

				// font
				if (typeof (ctx.font) != 'undefined') {
					ctx.font = svg.Font.CreateFont(
						this.style('font-style').value,
						this.style('font-variant').value,
						this.style('font-weight').value,
						this.style('font-size').hasValue() ? this.style('font-size').toPixels() + 'px' : '',
						this.style('font-family').value).toString();
				}

				// transform
				if (this.attribute('transform').hasValue()) {
					var transform = new svg.Transform(this.attribute('transform').value);
					transform.apply(ctx);
				}

				// clip
				if (this.attribute('clip-path').hasValue()) {
					var clip = this.attribute('clip-path').getDefinition();
					if (clip != null) clip.apply(ctx);
				}

				// opacity
				if (this.style('opacity').hasValue()) {
					ctx.globalAlpha = this.style('opacity').numValue();
				}
			}
		}
		svg.Element.RenderedElementBase.prototype = new svg.Element.ElementBase;

		// 基础图形元素： rect, circle, ellipse, line, polygon 的基类
		svg.Element.PathElementBase = function (node) {
			this.base = svg.Element.RenderedElementBase;
			this.base(node);

			this.path = function (ctx) {
				if (ctx != null) ctx.beginPath(); // new Path();
				return new svg.BoundingBox();
			}

			// 每个子对象都会单独渲染，如果对象重叠且填充，会造成同一个位置被打标多次
			this.renderChildren = function (ctx) {
				// 先描边再填充
				if (ctx.strokeStyle != '') {
					this.path(ctx);
					ctx.stroke();
				} 
				if (ctx.fillStyle != '' && ctx.fillStyle != 'rgb(255,255,255)' ) {
					ctx.setFillAngleTransform();
					this.path(ctx);
					ctx.fill();
				}
				ctx.updateBoundingBox(); // 更新区域预览

				var markers = this.getMarkers();
				if (markers != null) {
					if (this.style('marker-start').isUrlDefinition()) {
						var marker = this.style('marker-start').getDefinition();
						marker.render(ctx, markers[0][0], markers[0][1]);
					}
					if (this.style('marker-mid').isUrlDefinition()) {
						var marker = this.style('marker-mid').getDefinition();
						for (var i = 1; i < markers.length - 1; i++) {
							marker.render(ctx, markers[i][0], markers[i][1]);
						}
					}
					if (this.style('marker-end').isUrlDefinition()) {
						var marker = this.style('marker-end').getDefinition();
						marker.render(ctx, markers[markers.length - 1][0], markers[markers.length - 1][1]);
					}
				}
			}

			this.getBoundingBox = function () {
				return this.path();
			}

			this.getMarkers = function () {
				return null;
			}
		}
		svg.Element.PathElementBase.prototype = new svg.Element.RenderedElementBase;

		// svg element
		svg.Element.svg = function (node) {
			this.base = svg.Element.RenderedElementBase;
			this.base(node);

			this.baseClearContext = this.clearContext;
			this.clearContext = function (ctx) {
				this.baseClearContext(ctx);
				svg.ViewPort.RemoveCurrent();
			}

			this.baseSetContext = this.setContext;
			this.setContext = function (ctx) {
				// initial values
				ctx.strokeStyle = 'rgba(0,0,0,0)';
				ctx.lineCap = 'butt';
				ctx.lineJoin = 'miter';
				ctx.miterLimit = 4;

				this.baseSetContext(ctx);

				// create new view port
				if (!this.attribute('x').hasValue()) this.attribute('x', true).value = 0;
				if (!this.attribute('y').hasValue()) this.attribute('y', true).value = 0;
				ctx.translate(this.attribute('x').toPixels('x'), this.attribute('y').toPixels('y'));

				var width = svg.ViewPort.width();
				var height = svg.ViewPort.height();

				if (!this.attribute('width').hasValue()) this.attribute('width', true).value = '100%';
				if (!this.attribute('height').hasValue()) this.attribute('height', true).value = '100%';
				if (typeof (this.root) == 'undefined') {
					width = this.attribute('width').toPixels('x');
					height = this.attribute('height').toPixels('y');

					var x = 0;
					var y = 0;
					if (this.attribute('refX').hasValue() && this.attribute('refY').hasValue()) {
						x = -this.attribute('refX').toPixels('x');
						y = -this.attribute('refY').toPixels('y');
					}

					ctx.beginPath();
					ctx.moveTo(x, y);
					ctx.lineTo(width, y);
					ctx.lineTo(width, height);
					ctx.lineTo(x, height);
					ctx.closePath();
					ctx.clip();
				}
				svg.ViewPort.SetCurrent(width, height);

				// viewbox
				if (this.attribute('viewBox').hasValue()) {
					var viewBox = svg.ToNumberArray(this.attribute('viewBox').value);
					var minX = viewBox[0];
					var minY = viewBox[1];
					width = viewBox[2];
					height = viewBox[3];

					svg.AspectRatio(ctx,
						this.attribute('preserveAspectRatio').value,
						svg.ViewPort.width(),
						width,
						svg.ViewPort.height(),
						height,
						minX,
						minY,
						this.attribute('refX').value,
						this.attribute('refY').value);

					svg.ViewPort.RemoveCurrent();
					svg.ViewPort.SetCurrent(viewBox[2], viewBox[3]);
				}
			}
		}
		svg.Element.svg.prototype = new svg.Element.RenderedElementBase;

		// rect element
		svg.Element.rect = function (node) {
			this.base = svg.Element.PathElementBase;
			this.base(node);

			this.path = function (ctx) {
				var x = this.attribute('x').toPixels('x');
				var y = this.attribute('y').toPixels('y');
				var width = this.attribute('width').toPixels('x');
				var height = this.attribute('height').toPixels('y');
				var rx = this.attribute('rx').toPixels('x');
				var ry = this.attribute('ry').toPixels('y');
				if (this.attribute('rx').hasValue() && !this.attribute('ry').hasValue()) ry = rx;
				if (this.attribute('ry').hasValue() && !this.attribute('rx').hasValue()) rx = ry;
				// 圆角半径 rx 和 ry
				if (ctx != null) {
					ctx.beginPath();
					ctx.moveTo(x + rx, y);
					ctx.lineTo(x + width - rx, y);
					if(ry && ry != 0) ctx.quadraticCurveTo(x + width, y, x + width, y + ry)
					ctx.lineTo(x + width, y + height - ry);
					if(rx && rx != 0) ctx.quadraticCurveTo(x + width, y + height, x + width - rx, y + height)
					ctx.lineTo(x + rx, y + height);
					if(ry && ry != 0) ctx.quadraticCurveTo(x, y + height, x, y + height - ry)
					ctx.lineTo(x, y + ry);
					if(rx && rx != 0) ctx.quadraticCurveTo(x, y, x + rx, y)
					ctx.closePath();
				}

				return new svg.BoundingBox(x, y, x + width, y + height);
			}
		}
		svg.Element.rect.prototype = new svg.Element.PathElementBase;

		// circle element
		svg.Element.circle = function (node) {
			this.base = svg.Element.PathElementBase;
			this.base(node);

			this.path = function (ctx) {
				var cx = this.attribute('cx').toPixels('x');
				var cy = this.attribute('cy').toPixels('y');
				var r = this.attribute('r').toPixels();

				if (ctx != null) {
					ctx.beginPath();
					ctx.arc(cx, cy, r, 0, Math.PI * 2, true);
					ctx.closePath();
				}

				return new svg.BoundingBox(cx - r, cy - r, cx + r, cy + r);
			}
		}
		svg.Element.circle.prototype = new svg.Element.PathElementBase;

		// ellipse element
		svg.Element.ellipse = function (node) {
			this.base = svg.Element.PathElementBase;
			this.base(node);

			this.path = function (ctx) {
				var KAPPA = 4 * ((Math.sqrt(2) - 1) / 3);
				var rx = this.attribute('rx').toPixels('x');
				var ry = this.attribute('ry').toPixels('y');
				var cx = this.attribute('cx').toPixels('x');
				var cy = this.attribute('cy').toPixels('y');

				if (ctx != null) {
					ctx.beginPath();
					ctx.moveTo(cx, cy - ry);
					ctx.bezierCurveTo(cx + (KAPPA * rx), cy - ry, cx + rx, cy - (KAPPA * ry), cx + rx, cy);
					ctx.bezierCurveTo(cx + rx, cy + (KAPPA * ry), cx + (KAPPA * rx), cy + ry, cx, cy + ry);
					ctx.bezierCurveTo(cx - (KAPPA * rx), cy + ry, cx - rx, cy + (KAPPA * ry), cx - rx, cy);
					ctx.bezierCurveTo(cx - rx, cy - (KAPPA * ry), cx - (KAPPA * rx), cy - ry, cx, cy - ry);
					ctx.closePath();
				}

				return new svg.BoundingBox(cx - rx, cy - ry, cx + rx, cy + ry);
			}
		}
		svg.Element.ellipse.prototype = new svg.Element.PathElementBase;

		// line element
		svg.Element.line = function (node) {
			this.base = svg.Element.PathElementBase;
			this.base(node);

			this.getPoints = function () {
				return [
					new svg.Point(this.attribute('x1').toPixels('x'), this.attribute('y1').toPixels('y')),
					new svg.Point(this.attribute('x2').toPixels('x'), this.attribute('y2').toPixels('y'))];
			}

			this.path = function (ctx) {
				var points = this.getPoints();

				if (ctx != null) {
					ctx.beginPath();
					ctx.moveTo(points[0].x, points[0].y);
					ctx.lineTo(points[1].x, points[1].y);
				}

				return new svg.BoundingBox(points[0].x, points[0].y, points[1].x, points[1].y);
			}

			this.getMarkers = function () {
				var points = this.getPoints();
				var a = points[0].angleTo(points[1]);
				return [[points[0], a], [points[1], a]];
			}
		}
		svg.Element.line.prototype = new svg.Element.PathElementBase;

		// polyline element
		svg.Element.polyline = function (node) {
			this.base = svg.Element.PathElementBase;
			this.base(node);

			this.points = svg.CreatePath(this.attribute('points').value);
			this.path = function (ctx) {
				var bb = new svg.BoundingBox(this.points[0].x, this.points[0].y);
				if (ctx != null) {
					ctx.beginPath();
					ctx.moveTo(this.points[0].x, this.points[0].y);
				}
				for (var i = 1; i < this.points.length; i++) {
					bb.addPoint(this.points[i].x, this.points[i].y);
					if (ctx != null) ctx.lineTo(this.points[i].x, this.points[i].y);
				}
				return bb;
			}

			this.getMarkers = function () {
				var markers = [];
				for (var i = 0; i < this.points.length - 1; i++) {
					markers.push([this.points[i], this.points[i].angleTo(this.points[i + 1])]);
				}
				markers.push([this.points[this.points.length - 1], markers[markers.length - 1][1]]);
				return markers;
			}
		}
		svg.Element.polyline.prototype = new svg.Element.PathElementBase;

		// polygon element
		svg.Element.polygon = function (node) {
			this.base = svg.Element.polyline;
			this.base(node);

			this.basePath = this.path;
			this.path = function (ctx) {
				var bb = this.basePath(ctx);
				if (ctx != null) {
					ctx.lineTo(this.points[0].x, this.points[0].y);
					ctx.closePath();
				}
				return bb;
			}
		}
		svg.Element.polygon.prototype = new svg.Element.polyline;

		// path element
		svg.Element.path = function (node) {
			this.base = svg.Element.PathElementBase;
			this.base(node);

			var d = this.attribute('d').value;
			// TODO: convert to real lexer based on http://www.w3.org/TR/SVG11/paths.html#PathDataBNF
			d = d.replace(/,/gm, ' '); // get rid of all commas 将逗号替换为空格
			d = d.replace(/([MmZzLlHhVvCcSsQqTtAa])([MmZzLlHhVvCcSsQqTtAa])/gm, '$1 $2'); // separate commands from commands
			d = d.replace(/([MmZzLlHhVvCcSsQqTtAa])([MmZzLlHhVvCcSsQqTtAa])/gm, '$1 $2'); // separate commands from commands
			d = d.replace(/([MmZzLlHhVvCcSsQqTtAa])([^\s])/gm, '$1 $2'); // separate commands from points
			d = d.replace(/([^\s])([MmZzLlHhVvCcSsQqTtAa])/gm, '$1 $2'); // separate commands from points
			d = d.replace(/([0-9])([+\-])/gm, '$1 $2'); // separate digits when no comma 数字与正负号之间分隔开
			d = d.replace(/(\.[0-9]*)(\.)/gm, '$1 $2'); // separate digits when no comma
			d = d.replace(/([Aa](\s+[0-9]+){3})\s+([01])\s*([01])/gm, '$1 $3 $4 '); // shorthand elliptical arc path syntax
			d = svg.compressSpaces(d); // compress multiple spaces
			d = svg.trim(d);
			this.PathParser = new (function (d) {
				this.tokens = d.split(' ');

				this.reset = function () {
					this.i = -1;
					this.command = '';
					this.previousCommand = '';
					this.start = new svg.Point(0, 0);
					this.control = new svg.Point(0, 0);
					this.current = new svg.Point(0, 0);
					this.points = [];
					this.angles = [];
				}

				this.isEnd = function () {
					return this.i >= this.tokens.length - 1;
				}

				this.isCommandOrEnd = function () {
					if (this.isEnd()) return true;
					return this.tokens[this.i + 1].match(/^[A-Za-z]$/) != null;
				}

				this.isRelativeCommand = function () {
					switch (this.command) {
						case 'm':
						case 'l':
						case 'h':
						case 'v':
						case 'c':
						case 's':
						case 'q':
						case 't':
						case 'a':
						case 'z':
							return true;
							break;
					}
					return false;
				}

				this.getToken = function () {
					this.i++;
					return this.tokens[this.i];
				}

				this.getScalar = function () {
					return parseFloat(this.getToken());
				}

				this.nextCommand = function () {
					this.previousCommand = this.command;
					this.command = this.getToken();
				}

				this.getPoint = function () {
					var p = new svg.Point(this.getScalar(), this.getScalar());
					return this.makeAbsolute(p);
				}

				this.getAsControlPoint = function () {
					var p = this.getPoint();
					this.control = p;
					return p;
				}

				this.getAsCurrentPoint = function () {
					var p = this.getPoint();
					this.current = p;
					return p;
				}

				this.getReflectedControlPoint = function () {
					if (this.previousCommand.toLowerCase() != 'c' && this.previousCommand.toLowerCase() != 's') {
						return this.current;
					}

					// reflect point
					var p = new svg.Point(2 * this.current.x - this.control.x, 2 * this.current.y - this.control.y);
					return p;
				}

				this.makeAbsolute = function (p) {
					if (this.isRelativeCommand()) {
						p.x += this.current.x;
						p.y += this.current.y;
					}
					return p;
				}

				this.addMarker = function (p, from, priorTo) {
					// if the last angle isn't filled in because we didn't have this point yet ...
					if (priorTo != null && this.angles.length > 0 && this.angles[this.angles.length - 1] == null) {
						this.angles[this.angles.length - 1] = this.points[this.points.length - 1].angleTo(priorTo);
					}
					this.addMarkerAngle(p, from == null ? null : from.angleTo(p));
				}

				this.addMarkerAngle = function (p, a) {
					this.points.push(p);
					this.angles.push(a);
				}

				this.getMarkerPoints = function () { return this.points; }
				this.getMarkerAngles = function () {
					for (var i = 0; i < this.angles.length; i++) {
						if (this.angles[i] == null) {
							for (var j = i + 1; j < this.angles.length; j++) {
								if (this.angles[j] != null) {
									this.angles[i] = this.angles[j];
									break;
								}
							}
						}
					}
					return this.angles;
				}
			})(d);

			this.path = function (ctx) {
				var pp = this.PathParser;
				pp.reset();

				var bb = new svg.BoundingBox();
				if (ctx != null) ctx.beginPath();
				while (!pp.isEnd()) {
					pp.nextCommand();
					switch (pp.command) {
						case 'M':
						case 'm':
							var p = pp.getAsCurrentPoint();
							pp.addMarker(p);
							bb.addPoint(p.x, p.y);
							if (ctx != null) ctx.moveTo(p.x, p.y);
							pp.start = pp.current;
							while (!pp.isCommandOrEnd()) {
								var p = pp.getAsCurrentPoint();
								pp.addMarker(p, pp.start);
								bb.addPoint(p.x, p.y);
								if (ctx != null) ctx.lineTo(p.x, p.y);
							}
							break;
						case 'L':
						case 'l':
							while (!pp.isCommandOrEnd()) {
								var c = pp.current;
								var p = pp.getAsCurrentPoint();
								pp.addMarker(p, c);
								bb.addPoint(p.x, p.y);
								if (ctx != null) ctx.lineTo(p.x, p.y);
							}
							break;
						case 'H':
						case 'h':
							while (!pp.isCommandOrEnd()) {
								var newP = new svg.Point((pp.isRelativeCommand() ? pp.current.x : 0) + pp.getScalar(), pp.current.y);
								pp.addMarker(newP, pp.current);
								pp.current = newP;
								bb.addPoint(pp.current.x, pp.current.y);
								if (ctx != null) ctx.lineTo(pp.current.x, pp.current.y);
							}
							break;
						case 'V':
						case 'v':
							while (!pp.isCommandOrEnd()) {
								var newP = new svg.Point(pp.current.x, (pp.isRelativeCommand() ? pp.current.y : 0) + pp.getScalar());
								pp.addMarker(newP, pp.current);
								pp.current = newP;
								bb.addPoint(pp.current.x, pp.current.y);
								if (ctx != null) ctx.lineTo(pp.current.x, pp.current.y);
							}
							break;
						case 'C':
						case 'c':
							while (!pp.isCommandOrEnd()) {
								var curr = pp.current;
								var p1 = pp.getPoint();
								var cntrl = pp.getAsControlPoint();
								var cp = pp.getAsCurrentPoint();
								pp.addMarker(cp, cntrl, p1);
								bb.addBezierCurve(curr.x, curr.y, p1.x, p1.y, cntrl.x, cntrl.y, cp.x, cp.y);
								if (ctx != null) ctx.bezierCurveTo(p1.x, p1.y, cntrl.x, cntrl.y, cp.x, cp.y);
							}
							break;
						case 'S':
						case 's':
							while (!pp.isCommandOrEnd()) {
								var curr = pp.current;
								var p1 = pp.getReflectedControlPoint();
								var cntrl = pp.getAsControlPoint();
								var cp = pp.getAsCurrentPoint();
								pp.addMarker(cp, cntrl, p1);
								bb.addBezierCurve(curr.x, curr.y, p1.x, p1.y, cntrl.x, cntrl.y, cp.x, cp.y);
								if (ctx != null) ctx.bezierCurveTo(p1.x, p1.y, cntrl.x, cntrl.y, cp.x, cp.y);
							}
							break;
						case 'Q':
						case 'q':
							while (!pp.isCommandOrEnd()) {
								var curr = pp.current;
								var cntrl = pp.getAsControlPoint();
								var cp = pp.getAsCurrentPoint();
								pp.addMarker(cp, cntrl, cntrl);
								bb.addQuadraticCurve(curr.x, curr.y, cntrl.x, cntrl.y, cp.x, cp.y);
								if (ctx != null) ctx.quadraticCurveTo(cntrl.x, cntrl.y, cp.x, cp.y);
							}
							break;
						case 'T':
						case 't':
							while (!pp.isCommandOrEnd()) {
								var curr = pp.current;
								var cntrl = pp.getReflectedControlPoint();
								pp.control = cntrl;
								var cp = pp.getAsCurrentPoint();
								pp.addMarker(cp, cntrl, cntrl);
								bb.addQuadraticCurve(curr.x, curr.y, cntrl.x, cntrl.y, cp.x, cp.y);
								if (ctx != null) ctx.quadraticCurveTo(cntrl.x, cntrl.y, cp.x, cp.y);
							}
							break;
						case 'A':
						case 'a':
							while (!pp.isCommandOrEnd()) {
								var curr = pp.current;
								var rx = pp.getScalar();
								var ry = pp.getScalar();
								var xAxisRotation = pp.getScalar() * (Math.PI / 180.0);
								var largeArcFlag = pp.getScalar();
								var sweepFlag = pp.getScalar();
								var cp = pp.getAsCurrentPoint();

								// Conversion from endpoint to center parameterization
								// http://www.w3.org/TR/SVG11/implnote.html#ArcImplementationNotes
								// x1', y1'
								var currp = new svg.Point(
									Math.cos(xAxisRotation) * (curr.x - cp.x) / 2.0 + Math.sin(xAxisRotation) * (curr.y - cp.y) / 2.0,
									-Math.sin(xAxisRotation) * (curr.x - cp.x) / 2.0 + Math.cos(xAxisRotation) * (curr.y - cp.y) / 2.0
								);
								// adjust radii
								var l = Math.pow(currp.x, 2) / Math.pow(rx, 2) + Math.pow(currp.y, 2) / Math.pow(ry, 2);
								if (l > 1) {
									rx *= Math.sqrt(l);
									ry *= Math.sqrt(l);
								}
								// cx', cy'
								var s = (largeArcFlag == sweepFlag ? -1 : 1) * Math.sqrt(
									((Math.pow(rx, 2) * Math.pow(ry, 2)) - (Math.pow(rx, 2) * Math.pow(currp.y, 2)) - (Math.pow(ry, 2) * Math.pow(currp.x, 2))) /
									(Math.pow(rx, 2) * Math.pow(currp.y, 2) + Math.pow(ry, 2) * Math.pow(currp.x, 2))
								);
								if (isNaN(s)) s = 0;
								var cpp = new svg.Point(s * rx * currp.y / ry, s * -ry * currp.x / rx);
								// cx, cy
								var centp = new svg.Point(
									(curr.x + cp.x) / 2.0 + Math.cos(xAxisRotation) * cpp.x - Math.sin(xAxisRotation) * cpp.y,
									(curr.y + cp.y) / 2.0 + Math.sin(xAxisRotation) * cpp.x + Math.cos(xAxisRotation) * cpp.y
								);
								// vector magnitude
								var m = function (v) { return Math.sqrt(Math.pow(v[0], 2) + Math.pow(v[1], 2)); }
								// ratio between two vectors
								var r = function (u, v) { return (u[0] * v[0] + u[1] * v[1]) / (m(u) * m(v)) }
								// angle between two vectors
								var a = function (u, v) { return (u[0] * v[1] < u[1] * v[0] ? -1 : 1) * Math.acos(r(u, v)); }
								// initial angle
								var a1 = a([1, 0], [(currp.x - cpp.x) / rx, (currp.y - cpp.y) / ry]);
								// angle delta
								var u = [(currp.x - cpp.x) / rx, (currp.y - cpp.y) / ry];
								var v = [(-currp.x - cpp.x) / rx, (-currp.y - cpp.y) / ry];
								var ad = a(u, v);
								if (r(u, v) <= -1) ad = Math.PI;
								if (r(u, v) >= 1) ad = 0;

								if (sweepFlag == 0 && ad > 0) ad = ad - 2 * Math.PI;
								if (sweepFlag == 1 && ad < 0) ad = ad + 2 * Math.PI;

								// for markers
								var halfWay = new svg.Point(
									centp.x + rx * Math.cos((a1 + (a1 + ad)) / 2),
									centp.y + ry * Math.sin((a1 + (a1 + ad)) / 2)
								);
								pp.addMarkerAngle(halfWay, (a1 + (a1 + ad)) / 2 + (sweepFlag == 0 ? -1 : 1) * Math.PI / 2);
								pp.addMarkerAngle(cp, (a1 + ad) + (sweepFlag == 0 ? -1 : 1) * Math.PI / 2);

								bb.addPoint(cp.x, cp.y); // TODO: this is too naive, make it better
								if (ctx != null) {
									var r = rx > ry ? rx : ry;
									var sx = rx > ry ? 1 : rx / ry;
									var sy = rx > ry ? ry / rx : 1;

									ctx.translate(centp.x, centp.y);
									ctx.rotate(xAxisRotation);
									ctx.scale(sx, sy);
									ctx.arc(0, 0, r, a1, a1 + ad, 1 - sweepFlag);
									ctx.scale(1 / sx, 1 / sy);
									ctx.rotate(-xAxisRotation);
									ctx.translate(-centp.x, -centp.y);
								}
							}
							break;
						case 'Z':
						case 'z':
							if (ctx != null) ctx.closePath();
							pp.current = pp.start;
					}
				}

				return bb;
			}

			this.getMarkers = function () {
				var points = this.PathParser.getMarkerPoints();
				var angles = this.PathParser.getMarkerAngles();

				var markers = [];
				for (var i = 0; i < points.length; i++) {
					markers.push([points[i], angles[i]]);
				}
				return markers;
			}
		}
		svg.Element.path.prototype = new svg.Element.PathElementBase;

		// pattern element
		svg.Element.pattern = function (node) {
			this.base = svg.Element.ElementBase;
			this.base(node);

			this.createPattern = function (ctx, element) {
				// render me using a temporary svg element
				// var tempSvg = new svg.Element.svg();
				// tempSvg.attributes['viewBox'] = new svg.Property('viewBox', this.attribute('viewBox').value);
				// tempSvg.attributes['x'] = new svg.Property('x', this.attribute('x').value);
				// tempSvg.attributes['y'] = new svg.Property('y', this.attribute('y').value);
				// tempSvg.attributes['width'] = new svg.Property('width', this.attribute('width').value);
				// tempSvg.attributes['height'] = new svg.Property('height', this.attribute('height').value);
				// tempSvg.children = this.children;

				// var c = new Canvas();
				// c.width = this.attribute('width').toPixels('x') + this.attribute('x').toPixels('x');
				// c.height = this.attribute('height').toPixels('y') + this.attribute('y').toPixels('y');
				// tempSvg.render(c.getContext('2d'));
				// return ctx.createPattern(c, 'repeat');
				// 当前gcanvas未实现，
			}
		}
		svg.Element.pattern.prototype = new svg.Element.ElementBase;

		// marker element
		svg.Element.marker = function (node) {
			this.base = svg.Element.ElementBase;
			this.base(node);

			this.baseRender = this.render;
			this.render = function (ctx, point, angle) {
				ctx.translate(point.x, point.y);
				if (this.attribute('orient').valueOrDefault('auto') == 'auto') ctx.rotate(angle);
				if (this.attribute('markerUnits').valueOrDefault('strokeWidth') == 'strokeWidth') ctx.scale(ctx.lineWidth, ctx.lineWidth);
				ctx.save();

				// render me using a temporary svg element
				var tempSvg = new svg.Element.svg();
				tempSvg.attributes['viewBox'] = new svg.Property('viewBox', this.attribute('viewBox').value);
				tempSvg.attributes['refX'] = new svg.Property('refX', this.attribute('refX').value);
				tempSvg.attributes['refY'] = new svg.Property('refY', this.attribute('refY').value);
				tempSvg.attributes['width'] = new svg.Property('width', this.attribute('markerWidth').value);
				tempSvg.attributes['height'] = new svg.Property('height', this.attribute('markerHeight').value);
				tempSvg.attributes['fill'] = new svg.Property('fill', this.attribute('fill').valueOrDefault('black'));
				tempSvg.attributes['stroke'] = new svg.Property('stroke', this.attribute('stroke').valueOrDefault('none'));
				tempSvg.children = this.children;
				tempSvg.render(ctx);

				ctx.restore();
				if (this.attribute('markerUnits').valueOrDefault('strokeWidth') == 'strokeWidth') ctx.scale(1 / ctx.lineWidth, 1 / ctx.lineWidth);
				if (this.attribute('orient').valueOrDefault('auto') == 'auto') ctx.rotate(-angle);
				ctx.translate(-point.x, -point.y);
			}
		}
		svg.Element.marker.prototype = new svg.Element.ElementBase;

		// definitions element
		svg.Element.defs = function (node) {
			this.base = svg.Element.ElementBase;
			this.base(node);

			this.render = function (ctx) {
				// NOOP
			}
		}
		svg.Element.defs.prototype = new svg.Element.ElementBase;

		// base for gradients
		svg.Element.GradientBase = function (node) {
			this.base = svg.Element.ElementBase;
			this.base(node);

			this.gradientUnits = this.attribute('gradientUnits').valueOrDefault('objectBoundingBox');

			this.stops = [];
			for (var i = 0; i < this.children.length; i++) {
				var child = this.children[i];
				this.stops.push(child);
			}

			this.getGradient = function () {
				// OVERRIDE ME!
			}

			// TODO
			// this.createGradient = function (ctx, element) {
			// 	var stopsContainer = this;
			// 	if (this.attribute('xlink:href').hasValue()) {
			// 		stopsContainer = this.attribute('xlink:href').getDefinition();
			// 	}

			// 	var g = this.getGradient(ctx, element);
			// 	if (g == null) return stopsContainer.stops[stopsContainer.stops.length - 1].color;
			// 	for (var i = 0; i < stopsContainer.stops.length; i++) {
			// 		g.addColorStop(stopsContainer.stops[i].offset, stopsContainer.stops[i].color);
			// 	}

			// 	if (this.attribute('gradientTransform').hasValue()) {
			// 		// render as transformed pattern on temporary canvas
			// 		var rootView = svg.ViewPort.viewPorts[0];

			// 		var rect = new svg.Element.rect();
			// 		rect.attributes['x'] = new svg.Property('x', -svg.MAX_VIRTUAL_PIXELS / 3.0);
			// 		rect.attributes['y'] = new svg.Property('y', -svg.MAX_VIRTUAL_PIXELS / 3.0);
			// 		rect.attributes['width'] = new svg.Property('width', svg.MAX_VIRTUAL_PIXELS);
			// 		rect.attributes['height'] = new svg.Property('height', svg.MAX_VIRTUAL_PIXELS);

			// 		var group = new svg.Element.g();
			// 		group.attributes['transform'] = new svg.Property('transform', this.attribute('gradientTransform').value);
			// 		group.children = [rect];

			// 		var tempSvg = new svg.Element.svg();
			// 		tempSvg.attributes['x'] = new svg.Property('x', 0);
			// 		tempSvg.attributes['y'] = new svg.Property('y', 0);
			// 		tempSvg.attributes['width'] = new svg.Property('width', rootView.width);
			// 		tempSvg.attributes['height'] = new svg.Property('height', rootView.height);
			// 		tempSvg.children = [group];

			// 		var c = new Canvas();
			// 		c.width = rootView.width;
			// 		c.height = rootView.height;
			// 		var tempCtx = c.getContext('2d');
			// 		tempCtx.fillStyle = g;
			// 		tempSvg.render(tempCtx);
			// 		return tempCtx.createPattern(c, 'no-repeat');
			// 	}

			// 	return g;
			// }
		}
		svg.Element.GradientBase.prototype = new svg.Element.ElementBase;

		// linear gradient element
		svg.Element.linearGradient = function (node) {
			this.base = svg.Element.GradientBase;
			this.base(node);

			this.getGradient = function (ctx, element) {
				var bb = element.getBoundingBox();

				var x1 = (this.gradientUnits == 'objectBoundingBox'
					? bb.x() + bb.width() * this.attribute('x1').numValue()
					: this.attribute('x1').toPixels('x'));
				var y1 = (this.gradientUnits == 'objectBoundingBox'
					? bb.y() + bb.height() * this.attribute('y1').numValue()
					: this.attribute('y1').toPixels('y'));
				var x2 = (this.gradientUnits == 'objectBoundingBox'
					? bb.x() + bb.width() * this.attribute('x2').numValue()
					: this.attribute('x2').toPixels('x'));
				var y2 = (this.gradientUnits == 'objectBoundingBox'
					? bb.y() + bb.height() * this.attribute('y2').numValue()
					: this.attribute('y2').toPixels('y'));

				if (x1 == x2 && y1 == y2) return null;
				// return ctx.createLinearGradient(x1, y1, x2, y2); // TODO：暂时不支持渐变
			}
		}
		svg.Element.linearGradient.prototype = new svg.Element.GradientBase;

		// radial gradient element
		svg.Element.radialGradient = function (node) {
			this.base = svg.Element.GradientBase;
			this.base(node);

			this.getGradient = function (ctx, element) {
				var bb = element.getBoundingBox();

				if (!this.attribute('cx').hasValue()) this.attribute('cx', true).value = '50%';
				if (!this.attribute('cy').hasValue()) this.attribute('cy', true).value = '50%';
				if (!this.attribute('r').hasValue()) this.attribute('r', true).value = '50%';

				var cx = (this.gradientUnits == 'objectBoundingBox'
					? bb.x() + bb.width() * this.attribute('cx').numValue()
					: this.attribute('cx').toPixels('x'));
				var cy = (this.gradientUnits == 'objectBoundingBox'
					? bb.y() + bb.height() * this.attribute('cy').numValue()
					: this.attribute('cy').toPixels('y'));

				var fx = cx;
				var fy = cy;
				if (this.attribute('fx').hasValue()) {
					fx = (this.gradientUnits == 'objectBoundingBox'
						? bb.x() + bb.width() * this.attribute('fx').numValue()
						: this.attribute('fx').toPixels('x'));
				}
				if (this.attribute('fy').hasValue()) {
					fy = (this.gradientUnits == 'objectBoundingBox'
						? bb.y() + bb.height() * this.attribute('fy').numValue()
						: this.attribute('fy').toPixels('y'));
				}

				var r = (this.gradientUnits == 'objectBoundingBox'
					? (bb.width() + bb.height()) / 2.0 * this.attribute('r').numValue()
					: this.attribute('r').toPixels());

				// return ctx.createRadialGradient(fx, fy, 0, cx, cy, r); // TODO：暂时不支持渐变
			}
		}
		svg.Element.radialGradient.prototype = new svg.Element.GradientBase;

		// gradient stop element
		svg.Element.stop = function (node) {
			this.base = svg.Element.ElementBase;
			this.base(node);

			this.offset = this.attribute('offset').numValue();

			var stopColor = this.style('stop-color');
			if (this.style('stop-opacity').hasValue()) stopColor = stopColor.addOpacity(this.style('stop-opacity').value);
			this.color = stopColor.value;
		}
		svg.Element.stop.prototype = new svg.Element.ElementBase;

		// animation base element
		svg.Element.AnimateBase = function (node) {
			this.base = svg.Element.ElementBase;
			this.base(node);

			svg.Animations.push(this);

			this.duration = 0.0;
			this.begin = this.attribute('begin').toMilliseconds();
			this.maxDuration = this.begin + this.attribute('dur').toMilliseconds();

			this.getProperty = function () {
				var attributeType = this.attribute('attributeType').value;
				var attributeName = this.attribute('attributeName').value;

				if (attributeType == 'CSS') {
					return this.parent.style(attributeName, true);
				}
				return this.parent.attribute(attributeName, true);
			};

			this.initialValue = null;
			this.initialUnits = '';
			this.removed = false;

			this.calcValue = function () {
				// OVERRIDE ME!
				return '';
			}

			this.update = function (delta) {
				// set initial value
				if (this.initialValue == null) {
					this.initialValue = this.getProperty().value;
					this.initialUnits = this.getProperty().getUnits();
				}

				// if we're past the end time
				if (this.duration > this.maxDuration) {
					// loop for indefinitely repeating animations
					if (this.attribute('repeatCount').value == 'indefinite') {
						this.duration = 0.0
					}
					else if (this.attribute('fill').valueOrDefault('remove') == 'remove' && !this.removed) {
						this.removed = true;
						this.getProperty().value = this.initialValue;
						return true;
					}
					else {
						return false; // no updates made
					}
				}
				this.duration = this.duration + delta;

				// if we're past the begin time
				var updated = false;
				if (this.begin < this.duration) {
					var newValue = this.calcValue(); // tween

					if (this.attribute('type').hasValue()) {
						// for transform, etc.
						var type = this.attribute('type').value;
						newValue = type + '(' + newValue + ')';
					}

					this.getProperty().value = newValue;
					updated = true;
				}

				return updated;
			}

			this.from = this.attribute('from');
			this.to = this.attribute('to');
			this.values = this.attribute('values');
			if (this.values.hasValue()) this.values.value = this.values.value.split(';');

			// fraction of duration we've covered
			this.progress = function () {
				var ret = { progress: (this.duration - this.begin) / (this.maxDuration - this.begin) };
				if (this.values.hasValue()) {
					var p = ret.progress * (this.values.value.length - 1);
					var lb = Math.floor(p), ub = Math.ceil(p);
					ret.from = new svg.Property('from', parseFloat(this.values.value[lb]));
					ret.to = new svg.Property('to', parseFloat(this.values.value[ub]));
					ret.progress = (p - lb) / (ub - lb);
				}
				else {
					ret.from = this.from;
					ret.to = this.to;
				}
				return ret;
			}
		}
		svg.Element.AnimateBase.prototype = new svg.Element.ElementBase;

		// animate element
		svg.Element.animate = function (node) {
			this.base = svg.Element.AnimateBase;
			this.base(node);

			this.calcValue = function () {
				var p = this.progress();

				// tween value linearly
				var newValue = p.from.numValue() + (p.to.numValue() - p.from.numValue()) * p.progress;
				return newValue + this.initialUnits;
			};
		}
		svg.Element.animate.prototype = new svg.Element.AnimateBase;

		// animate color element
		svg.Element.animateColor = function (node) {
			this.base = svg.Element.AnimateBase;
			this.base(node);

			this.calcValue = function () {
				var p = this.progress();
				var from = new RGBColor(p.from.value);
				var to = new RGBColor(p.to.value);

				if (from.ok && to.ok) {
					// tween color linearly
					var r = from.r + (to.r - from.r) * p.progress;
					var g = from.g + (to.g - from.g) * p.progress;
					var b = from.b + (to.b - from.b) * p.progress;
					return 'rgb(' + parseInt(r, 10) + ',' + parseInt(g, 10) + ',' + parseInt(b, 10) + ')';
				}
				return this.attribute('from').value;
			};
		}
		svg.Element.animateColor.prototype = new svg.Element.AnimateBase;

		// animate transform element
		svg.Element.animateTransform = function (node) {
			this.base = svg.Element.animate;
			this.base(node);
		}
		svg.Element.animateTransform.prototype = new svg.Element.animate;

		// font element
		svg.Element.font = function (node) {
			this.base = svg.Element.ElementBase;
			this.base(node);

			this.horizAdvX = this.attribute('horiz-adv-x').numValue();

			this.isRTL = false;
			this.isArabic = false;
			this.fontFace = null;
			this.missingGlyph = null;
			this.glyphs = [];
			for (var i = 0; i < this.children.length; i++) {
				var child = this.children[i];
				if (child.type == 'font-face') {
					this.fontFace = child;
					if (child.style('font-family').hasValue()) {
						svg.Definitions[child.style('font-family').value] = this;
					}
				}
				else if (child.type == 'missing-glyph') this.missingGlyph = child;
				else if (child.type == 'glyph') {
					if (child.arabicForm != '') {
						this.isRTL = true;
						this.isArabic = true;
						if (typeof (this.glyphs[child.unicode]) == 'undefined') this.glyphs[child.unicode] = [];
						this.glyphs[child.unicode][child.arabicForm] = child;
					}
					else {
						this.glyphs[child.unicode] = child;
					}
				}
			}
		}
		svg.Element.font.prototype = new svg.Element.ElementBase;

		// font-face element
		svg.Element.fontface = function (node) {
			this.base = svg.Element.ElementBase;
			this.base(node);

			this.ascent = this.attribute('ascent').value;
			this.descent = this.attribute('descent').value;
			this.unitsPerEm = this.attribute('units-per-em').numValue();
		}
		svg.Element.fontface.prototype = new svg.Element.ElementBase;

		// missing-glyph element
		svg.Element.missingglyph = function (node) {
			this.base = svg.Element.path;
			this.base(node);

			this.horizAdvX = 0;
		}
		svg.Element.missingglyph.prototype = new svg.Element.path;

		// glyph element
		svg.Element.glyph = function (node) {
			this.base = svg.Element.path;
			this.base(node);

			this.horizAdvX = this.attribute('horiz-adv-x').numValue();
			this.unicode = this.attribute('unicode').value;
			this.arabicForm = this.attribute('arabic-form').value;
		}
		svg.Element.glyph.prototype = new svg.Element.path;

		// text element
		svg.Element.text = function (node) {
			this.base = svg.Element.RenderedElementBase;
			this.base(node);

			if (node != null) {
				// add children
				this.children = [];
				for (var i = 0; i < node.childNodes.length; i++) {
					var childNode = node.childNodes[i];
					if (childNode.nodeType == 1) { // capture tspan and tref nodes
						this.addChild(childNode, true);
					}
					else if (childNode.nodeType == 3) { // capture text
						this.addChild(new svg.Element.tspan(childNode), false);
					}
				}
			}

			this.baseSetContext = this.setContext;
			this.setContext = function (ctx) {
				this.baseSetContext(ctx);
				// TODO：暂时不支持以下属性
				// if (this.style('dominant-baseline').hasValue()) ctx.textBaseline = this.style('dominant-baseline').value;
				// if (this.style('alignment-baseline').hasValue()) ctx.textBaseline = this.style('alignment-baseline').value;
			}

			this.renderChildren = function (ctx) {
				var textAnchor = this.style('text-anchor').valueOrDefault('start');
				var x = this.attribute('x').toPixels('x');
				var y = this.attribute('y').toPixels('y');
				for (var i = 0; i < this.children.length; i++) {
					var child = this.children[i];

					if (child.attribute('x').hasValue()) {
						child.x = child.attribute('x').toPixels('x');
					}
					else {
						if (this.attribute('dx').hasValue()) y += this.attribute('dx').toPixels('x');
						if (child.attribute('dx').hasValue()) x += child.attribute('dx').toPixels('x');
						child.x = x;
					}

					var childLength = child.measureText(ctx);
					if (textAnchor != 'start' && (i == 0 || child.attribute('x').hasValue())) { // new group?
						// loop through rest of children
						var groupLength = childLength;
						for (var j = i + 1; j < this.children.length; j++) {
							var childInGroup = this.children[j];
							if (childInGroup.attribute('x').hasValue()) break; // new group
							groupLength += childInGroup.measureText(ctx);
						}
						child.x -= (textAnchor == 'end' ? groupLength : groupLength / 2.0);
					}
					x = child.x + childLength;

					if (child.attribute('y').hasValue()) {
						child.y = child.attribute('y').toPixels('y');
					}
					else {
						if (this.attribute('dy').hasValue()) y += this.attribute('dy').toPixels('y');
						if (child.attribute('dy').hasValue()) y += child.attribute('dy').toPixels('y');
						child.y = y;
					}
					y = child.y;

					child.render(ctx);
				}
			}
		}
		svg.Element.text.prototype = new svg.Element.RenderedElementBase;

		// text base
		svg.Element.TextElementBase = function (node) {
			this.base = svg.Element.RenderedElementBase;
			this.base(node);

			this.getGlyph = function (font, text, i) {
				var c = text[i];
				var glyph = null;
				if (font.isArabic) {
					var arabicForm = 'isolated';
					if ((i == 0 || text[i - 1] == ' ') && i < text.length - 2 && text[i + 1] != ' ') arabicForm = 'terminal';
					if (i > 0 && text[i - 1] != ' ' && i < text.length - 2 && text[i + 1] != ' ') arabicForm = 'medial';
					if (i > 0 && text[i - 1] != ' ' && (i == text.length - 1 || text[i + 1] == ' ')) arabicForm = 'initial';
					if (typeof (font.glyphs[c]) != 'undefined') {
						glyph = font.glyphs[c][arabicForm];
						if (glyph == null && font.glyphs[c].type == 'glyph') glyph = font.glyphs[c];
					}
				}
				else {
					glyph = font.glyphs[c];
				}
				if (glyph == null) glyph = font.missingGlyph;
				return glyph;
			}

			this.renderChildren = function (ctx) {
				var customFont = this.parent.style('font-family').getDefinition();
				if (customFont != null) {
					var fontSize = this.parent.style('font-size').numValueOrDefault(svg.Font.Parse(svg.ctx.font).fontSize);
					var fontStyle = this.parent.style('font-style').valueOrDefault(svg.Font.Parse(svg.ctx.font).fontStyle);
					var text = this.getText();
					if (customFont.isRTL) text = text.split("").reverse().join("");

					var dx = svg.ToNumberArray(this.parent.attribute('dx').value);
					for (var i = 0; i < text.length; i++) {
						var glyph = this.getGlyph(customFont, text, i);
						var scale = fontSize / customFont.fontFace.unitsPerEm;
						ctx.translate(this.x, this.y);
						ctx.scale(scale, -scale);
						var lw = ctx.lineWidth;
						ctx.lineWidth = ctx.lineWidth * customFont.fontFace.unitsPerEm / fontSize;
						if (fontStyle == 'italic') ctx.transform(1, 0, .4, 1, 0, 0);
						glyph.render(ctx);
						if (fontStyle == 'italic') ctx.transform(1, 0, -.4, 1, 0, 0);
						ctx.lineWidth = lw;
						ctx.scale(1 / scale, -1 / scale);
						ctx.translate(-this.x, -this.y);

						this.x += fontSize * (glyph.horizAdvX || customFont.horizAdvX) / customFont.fontFace.unitsPerEm;
						if (typeof (dx[i]) != 'undefined' && !isNaN(dx[i])) {
							this.x += dx[i];
						}
					}
					return;
				}

				if (ctx.strokeStyle != '') ctx.strokeText(svg.compressSpaces(this.getText()), this.x, this.y);
				if (ctx.fillStyle != '') ctx.fillText(svg.compressSpaces(this.getText()), this.x, this.y);
			}

			this.getText = function () {
				// OVERRIDE ME
			}

			this.measureText = function (ctx) {
				var customFont = this.parent.style('font-family').getDefinition();
				if (customFont != null) {
					var fontSize = this.parent.style('font-size').numValueOrDefault(svg.Font.Parse(svg.ctx.font).fontSize);
					var measure = 0;
					var text = this.getText();
					if (customFont.isRTL) text = text.split("").reverse().join("");
					var dx = svg.ToNumberArray(this.parent.attribute('dx').value);
					for (var i = 0; i < text.length; i++) {
						var glyph = this.getGlyph(customFont, text, i);
						measure += (glyph.horizAdvX || customFont.horizAdvX) * fontSize / customFont.fontFace.unitsPerEm;
						if (typeof (dx[i]) != 'undefined' && !isNaN(dx[i])) {
							measure += dx[i];
						}
					}
					return measure;
				}

				var textToMeasure = svg.compressSpaces(this.getText());
				if (!ctx.measureText) return textToMeasure.length * 10;

				ctx.save();
				this.setContext(ctx);
				var width = ctx.measureText(textToMeasure).width;
				ctx.restore();
				return width;
			}
		}
		svg.Element.TextElementBase.prototype = new svg.Element.RenderedElementBase;

		// tspan 
		svg.Element.tspan = function (node) {
			this.base = svg.Element.TextElementBase;
			this.base(node);

			this.text = node.nodeType == 3 ? node.nodeValue : // text
				node.childNodes.length > 0 ? node.childNodes[0].nodeValue : // element
					node.text ? node.text : "";
			this.getText = function () {
				return this.text;
			}
		}
		svg.Element.tspan.prototype = new svg.Element.TextElementBase;

		// tref
		svg.Element.tref = function (node) {
			this.base = svg.Element.TextElementBase;
			this.base(node);

			this.getText = function () {
				var element = this.attribute('xlink:href').getDefinition();
				if (element != null) return element.children[0].getText();
			}
		}
		svg.Element.tref.prototype = new svg.Element.TextElementBase;

		// a element
		svg.Element.a = function (node) {
			this.base = svg.Element.TextElementBase;
			this.base(node);

			this.hasText = true;
			for (var i = 0; i < node.childNodes.length; i++) {
				if (node.childNodes[i].nodeType != 3) this.hasText = false;
			}

			// this might contain text
			this.text = this.hasText ? node.childNodes[0].nodeValue : '';
			this.getText = function () {
				return this.text;
			}

			this.baseRenderChildren = this.renderChildren;
			this.renderChildren = function (ctx) {
				if (this.hasText) {
					// render as text element
					this.baseRenderChildren(ctx);
					var fontSize = new svg.Property('fontSize', svg.Font.Parse(svg.ctx.font).fontSize);
				}
				else {
					// render as temporary group
					var g = new svg.Element.g();
					g.children = this.children;
					g.parent = this;
					g.render(ctx);
				}
			}
		}
		svg.Element.a.prototype = new svg.Element.TextElementBase;

		// image element
		svg.Element.image = function (node) {
			// TODO：当前不支持解析image标签
			// this.base = svg.Element.RenderedElementBase;
			// this.base(node);

			// var href = this.attribute('xlink:href').value;

			// svg.Images.push(this);
			// this.loaded = false;

			// if (href.substr(0, 5) === 'data:') {

			// 	var match = href.match(/^data:.+;base64,(.*)$/);
			// 	var buffer = new Buffer(match[1], 'base64');

			// 	this.img = new Canvas.Image;
			// 	this.img.src = buffer;
			// 	this.loaded = true;

			// } else {

			// 	var isSvg = href.match(/\.svg$/)
			// 	var self = this;

			// 	if (!isSvg) {
			// 		svg.remote(href, function (data) {
			// 			self.img = new Canvas.Image();
			// 			self.img.src = data;
			// 			self.loaded = true;
			// 		});
			// 	} else {
			// 		/* fix me */
			// 	}
			// }

			// this.renderChildren = function (ctx) {
			// 	var x = this.attribute('x').toPixels('x');
			// 	var y = this.attribute('y').toPixels('y');

			// 	var width = this.attribute('width').toPixels('x');
			// 	var height = this.attribute('height').toPixels('y');
			// 	if (width == 0 || height == 0) return;

			// 	ctx.save();
			// 	// TODO
			// 	// if (isSvg) {
			// 	// 	/* fix me */
			// 	// } else {
			// 	// 	ctx.translate(x, y);
			// 	// 	svg.AspectRatio(ctx,
			// 	// 		this.attribute('preserveAspectRatio').value,
			// 	// 		width,
			// 	// 		this.img.width,
			// 	// 		height,
			// 	// 		this.img.height,
			// 	// 		0,
			// 	// 		0);
			// 	// 	ctx.drawImage(this.img, 0, 0);
			// 	// }
			// 	ctx.restore();
			// }

			// this.getBoundingBox = function () {
			// 	var x = this.attribute('x').toPixels('x');
			// 	var y = this.attribute('y').toPixels('y');
			// 	var width = this.attribute('width').toPixels('x');
			// 	var height = this.attribute('height').toPixels('y');
			// 	return new svg.BoundingBox(x, y, x + width, y + height);
			// }
		}
		svg.Element.image.prototype = new svg.Element.RenderedElementBase;

		// group element
		svg.Element.g = function (node) {
			this.base = svg.Element.RenderedElementBase;
			this.base(node);

			this.getBoundingBox = function () {
				var bb = new svg.BoundingBox();
				for (var i = 0; i < this.children.length; i++) {
					bb.addBoundingBox(this.children[i].getBoundingBox());
				}
				return bb;
			};
		}
		svg.Element.g.prototype = new svg.Element.RenderedElementBase;

		// symbol element
		svg.Element.symbol = function (node) {
			this.base = svg.Element.RenderedElementBase;
			this.base(node);

			this.baseSetContext = this.setContext;
			this.setContext = function (ctx) {
				this.baseSetContext(ctx);

				// viewbox
				if (this.attribute('viewBox').hasValue()) {
					var viewBox = svg.ToNumberArray(this.attribute('viewBox').value);
					var minX = viewBox[0];
					var minY = viewBox[1];
					width = viewBox[2];
					height = viewBox[3];

					svg.AspectRatio(ctx,
						this.attribute('preserveAspectRatio').value,
						this.attribute('width').toPixels('x'),
						width,
						this.attribute('height').toPixels('y'),
						height,
						minX,
						minY);

					svg.ViewPort.SetCurrent(viewBox[2], viewBox[3]);
				}
			}
		}
		svg.Element.symbol.prototype = new svg.Element.RenderedElementBase;

		// style element
		svg.Element.style = function (node) {
			this.base = svg.Element.ElementBase;
			this.base(node);

			// text, or spaces then CDATA
			var css = node.childNodes[0].nodeValue + (node.childNodes.length > 1 ? node.childNodes[1].nodeValue : '');
			css = css.replace(/(\/\*([^*]|[\r\n]|(\*+([^*\/]|[\r\n])))*\*+\/)|(^[\s]*\/\/.*)/gm, ''); // remove comments
			css = svg.compressSpaces(css); // replace whitespace
			var cssDefs = css.split('}');
			for (var i = 0; i < cssDefs.length; i++) {
				if (svg.trim(cssDefs[i]) != '') {
					var cssDef = cssDefs[i].split('{');
					var cssClasses = cssDef[0].split(',');
					var cssProps = cssDef[1].split(';');
					for (var j = 0; j < cssClasses.length; j++) {
						var cssClass = svg.trim(cssClasses[j]);
						if (cssClass != '') {
							var props = {};
							for (var k = 0; k < cssProps.length; k++) {
								var prop = cssProps[k].indexOf(':');
								var name = cssProps[k].substr(0, prop);
								var value = cssProps[k].substr(prop + 1, cssProps[k].length - prop);
								if (name != null && value != null) {
									props[svg.trim(name)] = new svg.Property(svg.trim(name), svg.trim(value));
								}
							}
							svg.Styles[cssClass] = props;
							if (cssClass == '@font-face') {
								var fontFamily = props['font-family'].value.replace(/"/g, '');
								var srcs = props['src'].value.split(',');
								for (var s = 0; s < srcs.length; s++) {
									if (srcs[s].indexOf('format("svg")') > 0) {
										var urlStart = srcs[s].indexOf('url');
										var urlEnd = srcs[s].indexOf(')', urlStart);
										var url = srcs[s].substr(urlStart + 5, urlEnd - urlStart - 6);
										svg.ajax(url, function (data) {
											var doc = svg.parseXml(data);
											var fonts = doc.getElementsByTagName('font');
											for (var f = 0; f < fonts.length; f++) {
												var font = svg.CreateElement(fonts[f]);
												svg.Definitions[fontFamily] = font;
											}
										});
									}
								}
							}
						}
					}
				}
			}
		}
		svg.Element.style.prototype = new svg.Element.ElementBase;

		// use element 
		svg.Element.use = function (node) {
			this.base = svg.Element.RenderedElementBase;
			this.base(node);

			this.baseSetContext = this.setContext;
			this.setContext = function (ctx) {
				this.baseSetContext(ctx);
				if (this.attribute('x').hasValue()) ctx.translate(this.attribute('x').toPixels('x'), 0);
				if (this.attribute('y').hasValue()) ctx.translate(0, this.attribute('y').toPixels('y'));
			}

			this.getDefinition = function () {
				var element = this.attribute('xlink:href').getDefinition();
				if (this.attribute('width').hasValue()) element.attribute('width', true).value = this.attribute('width').value;
				if (this.attribute('height').hasValue()) element.attribute('height', true).value = this.attribute('height').value;
				return element;
			}

			this.path = function (ctx) {
				var element = this.getDefinition();
				if (element != null) element.path(ctx);
			}

			this.renderChildren = function (ctx) {
				var element = this.getDefinition();
				if (element != null) {
					// temporarily detach from parent and render
					var oldParent = element.parent;
					element.parent = null;
					element.render(ctx);
					element.parent = oldParent;
				}
			}
		}
		svg.Element.use.prototype = new svg.Element.RenderedElementBase;

		// mask element
		svg.Element.mask = function (node) {
			// TODO：当前不支持解析mask标签
			// this.base = svg.Element.ElementBase;
			// this.base(node);

			// this.apply = function (ctx, element) {
			// 	// render as temp svg	
			// 	var x = this.attribute('x').toPixels('x');
			// 	var y = this.attribute('y').toPixels('y');
			// 	var width = this.attribute('width').toPixels('x');
			// 	var height = this.attribute('height').toPixels('y');

			// 	// temporarily remove mask to avoid recursion
			// 	var mask = element.attribute('mask').value;
			// 	element.attribute('mask').value = '';

			// 	var cMask = new Canvas();
			// 	cMask.width = x + width;
			// 	cMask.height = y + height;
			// 	var maskCtx = cMask.getContext('2d');
			// 	this.renderChildren(maskCtx);

			// 	var c = new Canvas();
			// 	c.width = x + width;
			// 	c.height = y + height;
			// 	var tempCtx = c.getContext('2d');
			// 	element.render(tempCtx);
			// 	tempCtx.globalCompositeOperation = 'destination-in';
			// 	tempCtx.fillStyle = maskCtx.createPattern(cMask, 'no-repeat');
			// 	tempCtx.fillRect(0, 0, x + width, y + height);

			// 	ctx.fillStyle = tempCtx.createPattern(c, 'no-repeat');
			// 	ctx.fillRect(0, 0, x + width, y + height);

			// 	// reassign mask
			// 	element.attribute('mask').value = mask;
			// }

			// this.render = function (ctx) {
			// 	// NO RENDER
			// }
		}
		svg.Element.mask.prototype = new svg.Element.ElementBase;

		// clip element
		svg.Element.clipPath = function (node) {
			this.base = svg.Element.ElementBase;
			this.base(node);

			this.apply = function (ctx) {
				for (var i = 0; i < this.children.length; i++) {
					if (this.children[i].path) {
						ctx.save();
						if(this.children[i].attributes.transform.value){
							var transform = new svg.Transform(this.children[i].attributes.transform.value);
							transform.apply(ctx);
						}
						
						this.children[i].path(ctx);
						ctx.clip();
						ctx.restore();
					}
				}
			}

			this.render = function (ctx) {
				// NO RENDER
			}
		}
		svg.Element.clipPath.prototype = new svg.Element.ElementBase;

		// filters
		svg.Element.filter = function (node) {
			// TODO：当前不支持解析filter标签
			// this.base = svg.Element.ElementBase;
			// this.base(node);

			// this.apply = function (ctx, element) {
			// 	// render as temp svg	
			// 	var bb = element.getBoundingBox();
			// 	var x = this.attribute('x').toPixels('x');
			// 	var y = this.attribute('y').toPixels('y');
			// 	if (x == 0 || y == 0) {
			// 		x = bb.x1;
			// 		y = bb.y1;
			// 	}
			// 	var width = this.attribute('width').toPixels('x');
			// 	var height = this.attribute('height').toPixels('y');
			// 	if (width == 0 || height == 0) {
			// 		width = bb.width();
			// 		height = bb.height();
			// 	}

			// 	// temporarily remove filter to avoid recursion
			// 	var filter = element.style('filter').value;
			// 	element.style('filter').value = '';

			// 	// max filter distance
			// 	var extraPercent = .20;
			// 	var px = extraPercent * width;
			// 	var py = extraPercent * height;

			// 	var c = new Canvas();
			// 	c.width = width + 2 * px;
			// 	c.height = height + 2 * py;
			// 	var tempCtx = c.getContext('2d');
			// 	tempCtx.translate(-x + px, -y + py);
			// 	element.render(tempCtx);

			// 	// apply filters
			// 	for (var i = 0; i < this.children.length; i++) {
			// 		this.children[i].apply(tempCtx, 0, 0, width + 2 * px, height + 2 * py);
			// 	}

			// 	// render on me
			// 	ctx.drawImage(c, 0, 0, width + 2 * px, height + 2 * py, x - px, y - py, width + 2 * px, height + 2 * py);

			// 	// reassign filter
			// 	element.style('filter', true).value = filter;
			// }

			// this.render = function (ctx) {
			// 	// NO RENDER
			// }
		}
		svg.Element.filter.prototype = new svg.Element.ElementBase;

		svg.Element.feGaussianBlur = function (node) {
			this.base = svg.Element.ElementBase;
			this.base(node);

			// TODO

			// function blur(ctx, width, height, sigma) {
			// 	var srcData = ctx.getImageData(0, 0, width, height);
			// 	stackblur.blur(srcData.data, width, height, sigma);
			// 	ctx.putImageData(srcData, 0, 0);
			// }

			// this.apply = function (ctx, x, y, width, height) {
			// 	// assuming x==0 && y==0 for now
			// 	blur(ctx, width, height, this.attribute('stdDeviation').numValue());
			// }
		}
		svg.Element.filter.prototype = new svg.Element.feGaussianBlur;

		// title element, do nothing
		svg.Element.title = function (node) {
		}
		svg.Element.title.prototype = new svg.Element.ElementBase;

		// desc element, do nothing
		svg.Element.desc = function (node) {
		}
		svg.Element.desc.prototype = new svg.Element.ElementBase;

		svg.Element.MISSING = function (node) {
			if (console) console.log('ERROR: Element \'' + node.nodeName + '\' not yet implemented.');
		}
		svg.Element.MISSING.prototype = new svg.Element.ElementBase;

		// element factory
		svg.CreateElement = function (node) {
			var className = node.nodeName.replace(/^[^:]+:/, ''); // remove namespace
			className = className.replace(/\-/g, ''); // remove dashes
			var e = null;
			if (typeof (svg.Element[className]) != 'undefined') {
				e = new svg.Element[className](node);
			}
			else {
				e = new svg.Element.MISSING(node);
			}

			e.type = node.nodeName;
			return e;
		}

		svg.loadXmlDoc = function (ctx, dom) {
			svg.init(ctx);

			var mapXY = function (p) {
				var e = ctx.canvas;
				while (e) {
					p.x -= e.offsetLeft;
					p.y -= e.offsetTop;
					e = e.offsetParent;
				}
				if (window.scrollX) p.x += window.scrollX;
				if (window.scrollY) p.y += window.scrollY;
				return p;
			}

			var e = svg.CreateElement(dom.documentElement);
			e.root = true;

			// render loop
			var isFirstRender = true;
			var draw = function () {
				svg.ViewPort.Clear();
				if (ctx.canvas.parentNode) svg.ViewPort.SetCurrent(ctx.canvas.parentNode.clientWidth, ctx.canvas.parentNode.clientHeight);

				if (svg.opts['ignoreDimensions'] != true) {
					// set canvas size
					if (e.style('width').hasValue()) {
						ctx.canvas.width = e.style('width').toPixels('x');
					}
					if (e.style('height').hasValue()) {
						ctx.canvas.height = e.style('height').toPixels('y');
					}
				}
				var cWidth = ctx.canvas.clientWidth || ctx.canvas.width;
				var cHeight = ctx.canvas.clientHeight || ctx.canvas.height;
				if (svg.opts['ignoreDimensions'] == true && e.style('width').hasValue() && e.style('height').hasValue()) {
					cWidth = e.style('width').toPixels('x');
					cHeight = e.style('height').toPixels('y');
				}
				svg.ViewPort.SetCurrent(cWidth, cHeight);

				if (!("ignoreAnimation" in svg.opts)) svg.opts.ignoreAnimation = false;

				if (svg.opts['offsetX'] != null) e.attribute('x', true).value = svg.opts['offsetX'];
				if (svg.opts['offsetY'] != null) e.attribute('y', true).value = svg.opts['offsetY'];
				if (svg.opts['scaleWidth'] != null && svg.opts['scaleHeight'] != null) {
					var xRatio = 1, yRatio = 1, viewBox = svg.ToNumberArray(e.attribute('viewBox').value);
					if (e.attribute('width').hasValue()) xRatio = e.attribute('width').toPixels('x') / svg.opts['scaleWidth'];
					else if (!isNaN(viewBox[2])) xRatio = viewBox[2] / svg.opts['scaleWidth'];
					if (e.attribute('height').hasValue()) yRatio = e.attribute('height').toPixels('y') / svg.opts['scaleHeight'];
					else if (!isNaN(viewBox[3])) yRatio = viewBox[3] / svg.opts['scaleHeight'];

					e.attribute('width', true).value = svg.opts['scaleWidth'];
					e.attribute('height', true).value = svg.opts['scaleHeight'];
					e.attribute('viewBox', true).value = '0 0 ' + (cWidth * xRatio) + ' ' + (cHeight * yRatio);
					e.attribute('preserveAspectRatio', true).value = 'none';
				}

				// clear and render
				if (svg.opts['ignoreClear'] != true) {
					ctx.clearRect(0, 0, cWidth, cHeight);
				}
				e.render(ctx);
				if (isFirstRender) {
					isFirstRender = false;
					if (typeof (svg.opts['renderCallback']) == 'function') svg.opts['renderCallback']();
				}
			}

			var waitingForImages = true;
			if (svg.ImagesLoaded()) {
				waitingForImages = false;
				draw();
			}
			svg.intervalID = setInterval(function () {
				var needUpdate = false;

				if (waitingForImages && svg.ImagesLoaded()) {
					waitingForImages = false;
					needUpdate = true;
				}

				// need update from redraw?
				if (typeof (svg.opts['forceRedraw']) == 'function') {
					if (svg.opts['forceRedraw']() == true) needUpdate = true;
				}

				// render if needed
				if (needUpdate) {
					draw();
					svg.Mouse.runEvents(); // run and clear our events
				}

				// stop after first render, since we just need one.
				if (svg.opts.ignoreAnimation && !isFirstRender) {
					svg.stop();
				}

			}, 1000 / svg.FRAMERATE);
		}

		svg.stop = function () {
			if (svg.intervalID) {
				clearInterval(svg.intervalID);
			}
		}

		svg.Mouse = new (function () {
			this.events = [];
			this.hasEvents = function () { return this.events.length != 0; }

			this.onclick = function (x, y) {
				this.events.push({
					type: 'onclick', x: x, y: y,
					run: function (e) { if (e.onclick) e.onclick(); }
				});
			}

			this.onmousemove = function (x, y) {
				this.events.push({
					type: 'onmousemove', x: x, y: y,
					run: function (e) { if (e.onmousemove) e.onmousemove(); }
				});
			}

			this.eventElements = [];

			// TODO
			// this.checkPath = function (element, ctx) {
			// 	for (var i = 0; i < this.events.length; i++) {
			// 		var e = this.events[i];
			// 		if (ctx.isPointInPath && ctx.isPointInPath(e.x, e.y)) this.eventElements[i] = element;
			// 	}
			// }

			this.checkBoundingBox = function (element, bb) {
				for (var i = 0; i < this.events.length; i++) {
					var e = this.events[i];
					if (bb.isPointInBox(e.x, e.y)) this.eventElements[i] = element;
				}
			}

			this.runEvents = function () {
				for (var i = 0; i < this.events.length; i++) {
					var e = this.events[i];
					var element = this.eventElements[i];
					while (element) {
						e.run(element);
						element = element.parent;
					}
				}

				// done running, clear
				this.events = [];
				this.eventElements = [];
			}
		});

		return svg;
	}
})();

module.exports = canvg;
